Active transport requires energy because it moves molecules across a membrane to a region of lower to higher concentration which is often against their concentration gradient or has an obstructing factor.
Answer:
The correct answer is "strengths: inexpensive, easy to culture, short life cycle, large number of offspring; weaknesses: invertebrate model, some diseases such as immunological cannot be modelled, anatomical features are very different from humans"
Explanation:
The fruit fly <em>Drosophila melanogaster</em> is one of the most used animal model for genetic and biomedical studies. There are many advantages of using Drosophila as model, including that it is very inexpensive to handle, it is easy to culture, it has a short life cycle allowing to observe the changes in phenotype very quickly and its large number of offspring allows to include several repetitions per trait in a study. However, there are some weaknesses of using Drosophila to study human biology. First, obviously the fruit fly is very different from humans, it is an invertebrate and its anatomical features are very different, which makes impossible to model some disorders such as immunological diseases.
Clouds form when moist, warm rising air cools and expands in the atmosphere. The water vapor in the air condenses to form tiny water droplets which are the basis of clouds.
Table salt contains iodine in it now.